Merge branch 'main' into chunk-data

Resolved 29 conflicting files. The notable decisions:

Confidence: main's tool-calling gate (RequiredProviderConfidence) and this
branch's local-RAG gate (DataConfidenceLevel) turned out to be the same rule
on the same axis, so they are now one field. Both tool results and data
sources raise it through RequireProviderConfidence(). The gate checks the
level strictly and no longer exempts providers trusted by configuration:
TrustedProviderIds is documented as applying to data-source security checks
only, and organizations set confidence through DataConfidence
.CustomConfidenceScheme instead. The security axis (DataSecurity, ERI,
IsTrustedForDataSourceSecurityChecks) is unchanged.

Provider creation: main's CreateProvider signature won (hfEndpointKind,
capabilityOverrides, no model parameter); tokenizerPath was added to it and
is set for every provider, including the new Hetzner, IONOS and LiteLLM.
Provider and EmbeddingProvider combine the record parameters, Lua parsing and
Lua serialization of both sides.

File types: main's hierarchy (ODT leaf, WORD parent, PowerPoint without the
legacy .ppt, TABULAR instead of DELIMITED_TABLE) plus this branch's
SPREADSHEET parent with ODS and the xlsm/xlsb/xla/xlam extensions, which the
runtime already reads. Both sides had added a conflicting HTML filter; the
reading family keeps the name, and the export path uses a narrow
HTML_DOCUMENT, following the existing LATEX/TEX split.

Runtime: main's file_data.rs is the base, including the prompt-injection
sanitizer and the extraction routes. Token counting and chunk segmentation
moved into take_released, so they act on the text the filter has released
rather than on text it is still holding. A failed count is logged and left
out instead of ending the extraction, because the app counts such a segment
itself.

Data sources: the participating-provider checks of this branch are kept, and
main's GetAllowedDataSources overload now builds on them. DirectChatService
resolves the launched chat's data source options before the check, so filter
and chat see the same options.

.NET and Rust both build clean; I18N regenerated to 4060 keys.

app/MindWork AI Studio/Tools/Services/DataSourceService.cs

@@ -50,6 +50,29 @@ public sealed class DataSourceService
             new("chat provider", usingTrustedProvider, selectedLLMProvider.GetConfidenceLevel(this.settingsManager)));
         return await this.GetDataSources(usingTrustedProvider, participatingProviders, previousSelectedDataSources);
     }
+
+    /// <summary>
+    /// Returns the requested data sources that are allowed for the selected LLM provider.
+    /// Unlike see GetDataSources(AIStudio.Settings.Provider, IReadOnlyCollection{IDataSource}),
+    /// this method checks only the supplied data sources.
+    /// </summary>
+    /// <param name="selectedLLMProvider">The selected LLM provider.</param>
+    /// <param name="dataSourceOptions">The active data source options, which determine which agent providers participate.</param>
+    /// <param name="requestedDataSources">The data sources to check.</param>
+    /// <returns>The requested data sources that are allowed for the provider.</returns>
+    public async Task<IReadOnlyList<IDataSource>> GetAllowedDataSources(AIStudio.Settings.Provider selectedLLMProvider, DataSourceOptions dataSourceOptions, IReadOnlyCollection<IDataSource> requestedDataSources)
+    {
+        if (selectedLLMProvider == Settings.Provider.NONE)
+        {
+            this.logger.LogWarning("The selected LLM provider is not set. We cannot filter the data sources by any means.");
+            return [];
+        }
+
+        var usingTrustedProvider = selectedLLMProvider.IsTrustedForDataSourceSecurityChecks(this.settingsManager);
+        var participatingProviders = this.GetParticipatingProviders(selectedLLMProvider.Id, dataSourceOptions,
+            new("chat provider", usingTrustedProvider, selectedLLMProvider.GetConfidenceLevel(this.settingsManager)));
+        return await this.GetAllowedDataSources(usingTrustedProvider, participatingProviders, requestedDataSources);
+    }
     
     /// <summary>
     /// Returns a list of data sources that are allowed for the selected LLM provider.
@@ -111,27 +134,31 @@ public sealed class DataSourceService
     {
         var allDataSources = this.settingsManager.ConfigurationData.DataSources.ToList();
         var previousSelectedDataSourceIds = previousSelectedDataSources?.Select(source => source.Id).ToHashSet(StringComparer.Ordinal) ?? [];
-        var filteredDataSources = new List<IDataSource>(allDataSources.Count);
-        var filteredSelectedDataSources = new List<IDataSource>(previousSelectedDataSourceIds.Count);
-        var tasks = new List<Task<IDataSource?>>(allDataSources.Count);
+        var filteredDataSources = await this.GetAllowedDataSources(usingTrustedProvider, participatingProviders, allDataSources);
+        var filteredSelectedDataSources = filteredDataSources.Where(source => previousSelectedDataSourceIds.Contains(source.Id)).ToList();
         
+        return new(filteredDataSources, filteredSelectedDataSources);
+    }
+
+    private async Task<IReadOnlyList<IDataSource>> GetAllowedDataSources(bool usingTrustedProvider, IReadOnlyList<ParticipatingProvider> participatingProviders, IReadOnlyCollection<IDataSource> requestedDataSources)
+    {
+        var filteredDataSources = new List<IDataSource>(requestedDataSources.Count);
+        var tasks = new List<Task<IDataSource?>>(requestedDataSources.Count);
+
         // Start all checks in parallel:
-        foreach (var source in allDataSources)
+        foreach (var source in requestedDataSources)
             tasks.Add(this.CheckOneDataSource(source, usingTrustedProvider, participatingProviders));
-        
+
+
         // Wait for all checks and collect the results:
         foreach (var task in tasks)
         {
             var source = await task;
             if (source is not null)
-            {
                 filteredDataSources.Add(source);
-                if (previousSelectedDataSourceIds.Contains(source.Id))
-                    filteredSelectedDataSources.Add(source);
-            }
         }
-        
-        return new(filteredDataSources, filteredSelectedDataSources);
+
+        return filteredDataSources;
     }
     
     private async Task<IDataSource?> CheckOneDataSource(IDataSource source, bool usingTrustedProvider, IReadOnlyList<ParticipatingProvider> participatingProviders)